Facebook's 750 million users around the world will now be able to chat with each other on camera, after the social networking giant announced a partnership with the internet telephony pioneer Skype.

Mark Zuckerberg, Facebook's founder, said last night that the website wanted to be "the social infrastructure" on top of which companies such as Skype build future products. And he tried out a new theme that looks likely to be central to Facebook's pitch to investors next year: it is not the number of users that the site has that is important, it is the amount of time they spend and the number of things they share while logged in.

Facebook users will be able to video-call with each other at the click of a button, said Mr Zuckerberg. "This type of thing is only possible because the social infrastructure already exists," he said. "We want to leave all the different types of apps toindependent entrepreneurs and companies that are going to be best in class. They will always do better than a company that is trying to do a million things."

Tony Bates, Skype's chief executive, who appeared alongside Mr Zuckerberg at yesterday's product unveiling, said his company, which was bought by Microsoft earlier this year, would also benefit hugely from the venture. "We get huge reach," he said. "There's no finer platform to stick your technology on top of."

Skype currently has about 170 million users, and carries 300 million minutes of video per month.